1. Field of the Invention
The present invention relates to an improved, automated disposal system for cleaning cat litter boxes.
2. Description of the Prior Art
In the past, various systems have been devised for cleaning cat litter boxes. Once such system is described in U.S. Pat. No. 4,862,830, which discloses an arrangement for cleaning soiled cat litter from a rectilinear cat litter box. This system employs a brush that moves the length of the cat litter box along two rails. However, the litter box must be configured with one end open down to the litter box floor so that the cat litter material can be discharged, since the brush is movable only along a linear path. Furthermore, this system is totally manual in operation.
U.S. Pat. No. 4,190,525 discloses a crank operated sifting screen mechanism for a cat litter box. A screen member fits into slots in the sides of the litter box. The litter box also requires a special configuration including inclined end walls. The litter box is alternatively raised at its right and left ends to rest on the flat, inclined end walls as the litter material passes back and forth through the screen to collect fecal matter. In an alternative arrangement a sifting screen tray is positioned at the bottom member of the cat litter box and is simply lifted by handles from the litter bed. Refuse is retained in the tray and litter passes through it to remain in the bed. Neither system is in any way automated. U.S. Pat. No. 4,854,267 discloses another cat litter box having a special configuration in which a litter sifting arrangement is operated manually.
U.S. Pat. No. 4,574,735 is directed to an electronically operated cat litter disposal system which employs a rotatable rake that is driven by a motor for sifting through litter. However, the cat litter box must be of a generally cylindrical configuration and specially constructed with a discharge groove. Other systems which employ rotatable sifting systems usable only for specially configured cat litter boxes are disclosed in U.S. Pat. Nos. 4,846,104 and 4,120,264. Heretofore, however, automated cat litter disposal systems have not been available for use with cat litter boxes of the type which are most widely used.
The cat litter boxes which are currently the most commercially successful are configured with walls forming a rectangular prism, or in a shape in which the walls are only very slightly sloped, thereby forming a trapezoidal prism. These conventional commercially available cat litter boxes have upright side walls and upright end walls so as to adequately confine cat litter material to a region directly above the floor of the cat litter box. The level of the litter material is substantially below the upper rim of the walls and below the walls of any opening to the cat litter box. This prevents the litter material from being scattered outside of the box.
Cats can be readily trained to utilize a cat litter box having a conventional construction of the type described for purposes of discharging excrement. A cat kept as a house pet will habitually enter such a cat litter box, defecate, and then cover the excrement produced with the litter material. Disposable cat litter material is commercially available which is scented to mask the unpleasant odors of the bodily wastes which are discharged. The portion of the cat litter material which is soiled will often tend to clump together when fecal matter is discharged on it.
Although cat litter material is usually scented to mask unpleasant odors, it can only be used for a limited period of time before the odors in the vicinity of the cat litter box become offensive. It is thereupon necessary for the owner of the pet to clean the litter box. The process of manually cleaning a cat litter box exposes the individual undertaking the task to very considerable odors which are released as the cat litter material is sifted from the cat litter box. The cleaning of a conventional cat litter box is therefore widely regarded as a very unpleasant task.